The present invention relates to an apparatus for bringing milk to a specific fat content in which whole milk and skimmed milk are mixed as they flow, and the skimmed milk is added according to the previously determined fat content of the whole milk, the flow quantities of whole milk and skimmed milk being measured continuously.
Processes of this type are required to determine the fat content of the milk as accurately as possible and thereby obtain so-called "standardized milk". In this process, whole milk and skimmed milk are combined, that is, the whole milk is diluted by the skimmed milk. In Germany, the minimum fat content of milk is a legal requirement. This minimum content is set at 3.5 percent and must be maintained. The same applies in England according to the new EEC regulations.
In the case of a known process of the type mentioned initially, the sample for determining the fat content of the whole milk is taken by hand from a large intermediate container of whole milk. The fat content of the whole milk is then determined and the amount of skimmed milk to be added, which is gauged therefrom, is manually adjusted. This adjustment process is then constantly repeated. This process is generally effected by supplying to a regulator which is also acted on by the whole milk and skim milk volume flow values and is connected in series with an adjusting valve, a nominal value for controlling the adjusting valve corresponding to the fat content of the sample.
A disadvantage of this known process is that milk cannot flow through the particular machinery either during the time of taking the sample or during the time of determining the fat content of the sample since until the fat content of the particular sample is determined, the amount of skimmed milk to be added is not known. However, if the mixture is produced by adding an amount of skimmed milk which corresponds to the previously taken sample, incorrect mixtures can be produced. This error is serious or even inadmissible if the fat content falls below that which is legally required. In addition, a relatively long period of time elapses between the time the sample is taken and the time when the amount of skimmed milk to be added is adjusted.